let V be RealLinearSpace; :: thesis: for A being Subset of V

for L1, L2 being Linear_Combination of V st L1 is Linear_Combination of A & L2 is Linear_Combination of A holds

L1 + L2 is Linear_Combination of A

let A be Subset of V; :: thesis: for L1, L2 being Linear_Combination of V st L1 is Linear_Combination of A & L2 is Linear_Combination of A holds

L1 + L2 is Linear_Combination of A

let L1, L2 be Linear_Combination of V; :: thesis: ( L1 is Linear_Combination of A & L2 is Linear_Combination of A implies L1 + L2 is Linear_Combination of A )

assume ( L1 is Linear_Combination of A & L2 is Linear_Combination of A ) ; :: thesis: L1 + L2 is Linear_Combination of A

then ( Carrier L1 c= A & Carrier L2 c= A ) by Def6;

then A1: (Carrier L1) \/ (Carrier L2) c= A by XBOOLE_1:8;

Carrier (L1 + L2) c= (Carrier L1) \/ (Carrier L2) by Th37;

hence Carrier (L1 + L2) c= A by A1; :: according to RLVECT_2:def 6 :: thesis: verum

for L1, L2 being Linear_Combination of V st L1 is Linear_Combination of A & L2 is Linear_Combination of A holds

L1 + L2 is Linear_Combination of A

let A be Subset of V; :: thesis: for L1, L2 being Linear_Combination of V st L1 is Linear_Combination of A & L2 is Linear_Combination of A holds

L1 + L2 is Linear_Combination of A

let L1, L2 be Linear_Combination of V; :: thesis: ( L1 is Linear_Combination of A & L2 is Linear_Combination of A implies L1 + L2 is Linear_Combination of A )

assume ( L1 is Linear_Combination of A & L2 is Linear_Combination of A ) ; :: thesis: L1 + L2 is Linear_Combination of A

then ( Carrier L1 c= A & Carrier L2 c= A ) by Def6;

then A1: (Carrier L1) \/ (Carrier L2) c= A by XBOOLE_1:8;

Carrier (L1 + L2) c= (Carrier L1) \/ (Carrier L2) by Th37;

hence Carrier (L1 + L2) c= A by A1; :: according to RLVECT_2:def 6 :: thesis: verum